Airbag lung

ABSTRACT

A method of inflating an airbag includes expanding a collapsed or folded frame that supports and expands the airbag. The expansion of the airbag creates a lower pressure in the interior of the airbag as compared to the exterior, which allows air to be drawn into the airbag due to the lower pressure to fill the airbag. The frame can be made from inflatable ribs, or the frame can be made from interconnecting rigid members. The inflatable ribs can be inflated using a compressed gas canister, while the frame made from rigid members can be expanded using a spring. Filling a frame made from inflatable ribs, as opposed to the airbag itself allows for a smaller compressed gas canister.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. U.S. 62/289,802, filed Feb. 1, 2016, which is hereby incorporated by reference in its entirety.

BACKGROUND

An avalanche airbag system is a self-protection product designed to reduce the chance for burial by the user if caught in an avalanche. These systems are carried by the user and have a deployable chamber that fills with gas to increase the user's buoyancy and overall volume to decrease the chances of burial. These systems try to balance weight and cost versus effectiveness. Generally, a larger, more voluminous airbag is favored. However, larger systems become burdensome to carry because of size and weight. Therefore, systems try to minimize the size and weight of the system without compromising the effectiveness. The airbag volume seems to be limited by the device that is tasked to fill the airbag. Some systems may use a closed system where a compressed gas canister contains all the air (or gas) needed to inflate the airbag. In other cases, the compressed gas may be routed through a Venturi valve before vented into the airbag. The Venturi valve creates a drop in pressure that then pulls in ambient air into the flow from the compressed gas, thus adding to the overall gas delivered into the airbag. By adding this type of valve, the gas canister can provide much more gas into the airbag than that provided by the gas canister alone. Other systems may omit compressed gas canisters because of their single use nature. Accordingly, some systems may use a mechanical air mover with rechargeable batteries.

SUMMARY

An airbag in accordance with one embodiment of the invention can require substantially less compressed gas to fill, thus minimizing the size of the gas canister or increasing the volume of the airbag that is substantially more than all the gas volume from the compressed gas canister. Instead of relying on pushing air into the airbag chamber to fill it, embodiments of the airbag in accordance with the invention expand the airbag outer surface and therefore create a lower pressure inside the airbag as compared to outside, which will naturally fill with ambient atmospheric air. The airbag outer surface may be expanded by different means. Some embodiments may use a rib structure inside (or outside) the airbag chamber. The rib structure can take the form of a frame made from rigid members that fold or collapse when not in use, and that can be sprung to expand the frame and cause inflation of the airbag. Another rib structure can be made from inflatable channels (ribs) that are inflated, instead of the airbag directly, with the compressed gas from the gas canister. The compressed gas canister, when deployed, will inflate the ribs which will expand the airbag chamber and create a vacuum on the inside of the airbag as the exterior airbag surface is increased by the tension as the ribs increase in pressure. The ribs surround and are connected to the airbag, so that as the ribs become rigid, the ribs support the airbag walls and force air into the airbag via the natural vacuum that is created. The airbag chamber can be connected to a one-way valve allowing ambient atmospheric air to enter the airbag but not allowed to leave the airbag. In some of the disclosed embodiments, the airbag does not require nearly the amount of compressed gas to fully inflate the airbag, because the compressed gas canister need only carry enough compressed gas to inflate the internal ribs. In some embodiments, a Venturi valve may be used with the compressed gas canister to increase the amount of air entering the rib structure.

Some embodiments relate to a method of inflating an airbag. The method includes inflating a collapsed inflatable frame that supports and expands walls of an airbag, creating a lower pressure in the interior of the airbag as compared to the exterior during expansion of the inflatable frame while allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag.

In some embodiments, the airbag is fluidly connected to a forced air device, such as a battery operated fan.

In some embodiments, the frame comprises inflatable ribs placed along the airbag walls.

In some embodiments, the frame comprises inflatable ribs that are formed by welding an outer membrane with an inner membrane.

In some embodiments, the frame comprises an enclosed pocket surrounding a majority of the airbag wall surface.

Some embodiments further include inflating the inflatable frame to a pressure to make the frame rigid.

In some embodiments, the frame receives gas from a gas storage device, and the airbag receives gas from the atmosphere.

In some embodiments, the gas storage device further includes a Venturi valve to increase the amount of air that is pushed into the airbag.

In some embodiments, the inflatable frame has a capacity that is less than a capacity of the airbag.

In some embodiments, the inflatable frame receives gas from a source that is a different source than the gas used to inflate the airbag.

Some embodiments relate to a method of inflating an airbag. The method includes, with a device, expanding a collapsed or folded frame that supports and expands airbag walls, creating a lower pressure in the interior of the airbag as compared to the exterior, and allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag, wherein the frame comprises rigid interconnecting members.

In some embodiments, the device is a torsion spring.

In some embodiments, the frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.

In some embodiments, the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.

Some embodiments are related to an airbag, which includes a thin membrane formed into a collapsed deflated bag with an inlet in communication to the atmosphere, a collapsed frame that is attached to walls of the bag, and a device connected to the frame, wherein the device is configured to expand the frame.

In some embodiments, the device includes a torsion spring connected to the frame.

In some embodiments, the collapsed frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.

In some embodiments, the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.

Some embodiments are related to an airbag, which includes a first thin interior membrane formed into a collapsed deflated bag with an inlet that allows air to enter from the atmosphere, a second thin exterior membrane juxtaposed on and surrounding the first thin membrane, wherein a first inflatable volume is created between the first and second membranes and a second inflatable volume is created in the interior of the first membrane, wherein the capacity of the first inflatable volume is less than the second inflatable volume.

In some embodiments, the first inflatable volume is connected to a compressed gas cylinder, and the second inflatable volume is connected to the ambient atmosphere.

In some embodiments, the first inflatable volume is connected to a forced air device.

In some embodiments, the first inflatable volume is connected to the second inflatable volume via a one-way valve.

The methods and airbags disclosed herein have use, for example, in avalanche protection devices.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1A is a diagrammatical illustration of an airbag;

FIG. 1B is a diagrammatical illustration of the airbag of FIG. 1A;

FIG. 2A is a diagrammatical illustration of a combination of an airbag and backpack;

FIG. 2B is a diagrammatical illustration of the combination of airbag and backpack of FIG. 2A;

FIG. 2C is a diagrammatical illustration of the combination of airbag and backpack of FIG. 2A;

FIG. 2D is a diagrammatical illustration of the combination of airbag and backpack of FIG. 2A;

FIG. 3A is a diagrammatical illustration of an airbag;

FIG. 3B is a diagrammatical illustration of the airbag of FIG. 3A;

FIG. 4A is a diagrammatical illustration of an airbag;

FIG. 4B is a diagrammatical illustration of the airbag of FIG. 4A; and

FIG. 5 is a diagrammatical illustration of an airbag.

DETAILED DESCRIPTION

Referring to FIG. 1A, one embodiment of an airbag system 100 is illustrated. The airbag system 100 includes an airbag 102 and a three-dimensional frame structure 104. The frame structure 104 is for supporting the walls of the airbag 102 to add volume. The frame structure 104 has two modes, an initial collapsed (or folded) mold and a rigidized or deployed mode. When in the collapsed mode, the airbag is deflated, while when the frame is in the rigid mode, the airbag is inflated. The process of going from the collapsed to rigidized mode causes the airbag to inflate via vacuum that is created inside the airbag. In the embodiments disclosed, “airbag” is used to refer to any chamber that holds gas of any type, including, but not limited to, air. The airbag systems disclosed herein may include features not shown, but which are known to be used with airbag systems, such as restraints, backpacks, and trigger mechanisms. The airbags may be used in safety devices for protection against burial in avalanches.

In the embodiment of FIGS. 1 A and 1B, the frame 104 is formed from a plurality of inflatable channels or ribs. The airbag 102 is made from a thin, flexible membrane that is generally gas impermeable. The membrane may be elastic in some embodiments. The airbag 102 is generally sealed on all sides to prevent gases from escaping therefrom. As its name implies, the airbag 102 is inflatable. The airbag 102 may be made from two or more thin similar or dissimilar layered materials. The airbag may be made from one or more thin membranes wherein each layer may provide for a specific function. For example, one layer may provide for gas impermeability, a second layer may provide for biaxial strength, and a third layer may provide for exterior puncture resistance. Materials for such uses are known in the art. The frame structure 104 may be placed on the interior or exterior of the airbag 102. In some embodiments, the rib structure 104 may include inflatable vertically and horizontally placed channels. However, either vertical or horizontal channels may be used alone. The channels themselves are sealed from the main airbag chamber and may constitute a closed system, wherein the airbag is also a separate closed system. That is, the rib structure 104 may have a separate and distinct gas source for inflating, and the airbag 102 may have a distinct and separate gas source for inflating. The rib structure 104 may be created by heat welding a layer next to the surface layer of the airbag 102 by welding the two juxtaposed layers in the horizontal and vertical directions and creating open, intersecting channels. The system of channels 104 is open to a gas inlet that is separate from the gas inlet of the airbag 102. Specifically, the gas inlet for the rib structure 104 includes a compressed gas cylinder or canister 108. The gas cylinder 108 connects to the rib system 104 via a tube. Optionally, a Venturi valve 114 may be included in the tube between the compressed gas cylinder 108 and the entrance to the rib structure 104. As explained in the Background section above, the Venturi valve 114 introduces a greater amount of gas than is otherwise available from the compressed gas cylinder 108 via the Venturi effect which creates a vacuum and draws in additional ambient air. Because the rib structure 104 requires less volume of gas to be inflated to a rigidized state than the airbag 102 chamber, the compressed gas cylinder 108 can be significantly reduced in size as compared to a gas cylinder that would be needed if the compressed gas cylinder were to inflate the entirety of the airbag chamber.

Activation and release of the compressed gas from the compressed gas cylinder 108 may be accomplished via several mechanisms. For example, the compressed gas cylinder may be activated by manual or automatic means. Manual means may include a ripcord-style mechanism. The compressed gas cylinder 108 may feed only the rib structure 104 to inflate and pressurize the rib structure 104 to a pressure that expands the rib structure outward as seen in FIG. 1B. As the rib structure 104 becomes inflated, the rib structure 104 is forced apart, thereby expanding the airbag 102 along with it. As the airbag 102 expands along with the rib′ structure, a lower pressure is created in the interior chamber 106 of the airbag, thereby causing a vacuum. A one-way valve 110 is provided solely to feed the airbag chamber 106. Once the air enters the airbag chamber 106, the air is prevented from leaving by the one-way valve 110.

A one-way valve 112 that connects the ribs 104 to the airbag 102 may also be provided that allows pressurization of the airbag chamber 106 above atmospheric pressure. The rib structure 104 is attached to and supports the walls of the airbag 102 such that as the rib structure 104 becomes pressurized, the rib structure causes the airbag walls to expand outward. Once the chambers of the rib structure 104 have been pressurized, the one-way valve 112 may allow pressurized gas to enter into the airbag chamber 106 from the rib structure 104.

As seen in FIG. 1B, the rib structure 104, when inflated, assumes a three-dimensional volume that makes for a rigid frame surrounding the inflated chamber of the airbag 102. The volume of gas that takes to inflate and pressurize the rib structure 104 is small in comparison to the overall volume of the airbag chamber 106. The rib structure 104 may be formed by welding and/or gluing an additional layer 116 juxtaposed on the airbag membrane in strategic directions so as to create inflatable channels.

Referring to FIGS. 2A, 2B, 2C, and 2D, another embodiment of an airbag system 200 is illustrated. The airbag system 200 may be mounted on a harness 206, such as in a backpack-style arrangement. It should be apparent that all airbag embodiments may be connected to the user via a harness, or mounted to a backpack that can then be attached to the user via a harness. The airbags are mountable on backpacks or are individually carried on a person's back.

In the embodiment illustrated in FIGS. 2A, 2B, 2C, and 2D, the airbag system 200 includes a frame 202 made from rigid interconnected members. As with the embodiment of FIGS. 1A and 1B, the frame 202 has a collapsed or folded mode and an expanded mode. In one embodiment, a collapsed frame 202 may be made from a plurality of rigid arc-shaped members. The rigid arc-shaped members can be nested within each other. While the individual arc-shaped members are rigid, the overall frame 202 is a foldable or collapsible to a small size when the airbag is not deployed. The frame unfolds or expands into a larger volume in order to deploy the airbag 208. The principle used in the embodiment of FIG. 2 is similar to the embodiment of FIG. 1 in that the frame 202 that supports and is connected to the airbag 208 is caused to expand, thereby expanding the walls of the airbag 208. Upon expansion, the interior airbag chamber experiences a lower pressure on the inside of the chamber as compared to the ambient exterior atmosphere, thereby causing air to rush into the airbag chamber. In FIG. 2B, the frame 202 is folded or collapsed to have minimal volume, and the airbag 208 is also folded and collapsed.

The frame 202 is made from individual arc-shaped members having two sides. All of the members are connected about a pivoting point on the same corresponding side. As can be appreciated, the members can swing about the pivot points thereby creating a larger volume from the initial folded mode. A torsion spring 204 may be connected coaxial with the pivot, wherein one end of the coil spring is attached to the first (or last) rigid arc-shaped member and the other end of the coil spring is attached to the last (or first) rigid arc-shaped member. A torsion spring is one that stores rotational energy, such as by coiling tighter. Energy is released when the coils unwind partly. In the case of the airbag 200, the torsion spring 204 stores energy and upon release, the spring 204 causes the last (or first) of the arc-shaped members to rotate away from the first (or last) arc-shaped member, thus expanding into a three-dimensional shape out of an essentially initial flat shape. The once flat assembly of rigid arc-shaped members are caused to revolve around the pivot point. The expanded shape may resemble part of a torus. However, the frame may take on other shapes as well. One or two springs 204 may be used, each on a separate end of the arc-shaped members, or a single spring that spans the width of the arc-shaped members. As shown in FIG. 2B, the individual arc-shaped members are in a position that minimizes the volume. An airbag 208 is draped over and attached to the frame 202, and the bag 208 is also collapsed and deflated, thereby presenting only a small volume when in the deflated state.

The airbag 208 includes a one-way valve 210. The valve 210 allows air to enter the airbag 208 but prevents air from escaping from the airbag 208. The springs 204 are under torsional force and are prevented from releasing by a type of trigger mechanism. The trigger mechanism may be manually activated, such as via a ripcord, for example. FIGS. 2C and 2D show the airbag system 200 in a deployed mode. The spring 204 has uncoiled, thereby moving the individual arc-shaped members apart by rotating the last member with respect to the first member. As the spring 204 expands the frame, the bag 208 supported on the frame expands with it, and thereby causes a lower pressure in the interior of the airbag as compared to the exterior.

Air is allowed to enter the airbag 208 via the one-way valve 210. As can be appreciated, the airbag system 200 does not rely on any compressed gas to fill the airbag 208. The airbag 208 is filled by creating a lower pressure in the interior of the airbag by expanding a frame 202 that supports and is connected to the walls of the airbag chamber 200.

Referring to FIGS. 3A and 3B, another embodiment of an airbag system 300 is illustrated. In the embodiment shown in FIGS. 3A and 3B, the airbag includes a first plate 302 and a second plate 304. The plates 302 and 304 are arranged such that the peripheries of the respective plates are inline. The plates 302 and 304 are rigid, rectangular-shaped, thin plates. In FIG. 3A, the plates are close to each other in a compressed or compacted state. An airbag is created by attaching a membrane 314 that connects the first plate 302 to the second plate 304 on the entire periphery of the plates 302, 304, so as to create a closed volume formed by the sides of the plates and the membrane 314. The first and the second plates 302, 304 may be connected via a linkage comprising a first rigid rod 306 and a second rigid rod 316. One end of the rod 306 is connected to plate 306, and one end of the rod 316 is connected to the plate 304. The opposite ends of rods 306, 316 are connected at a pivoting point. A torsion spring 308 is connected to the ends of the rods 306, 316 that are not connected to the plates. A second similar mechanical linkage comprising a third rod 310 and a fourth rod 310 and a second spring 312 may connect the plates 302 and 304 at a second location thereof. Similar linkages may also be provided on the opposite side of the plates 302, 304 (not shown). The airbag system 300 includes a one-way valve 322, for example, on the membrane material 314. The one-way valve 322 communicates with the interior chamber created by the sides of the plates 302, 304 and the thin, flexible membrane 314.

As shown in FIG. 3B, the torsion springs 308 and 312 have been released, thereby causing each pair of rods 306, 316, 310, and 320 to spring apart, thereby separating the plates 302 and 304 from each other. The act of causing the plates 302, 304 to separate from each other expands the sides of the airbag 314, thereby creating a lower pressure in the interior of the airbag 314 as compared to the exterior. Air is drawn into the interior of the airbag 314 by the one-way valve 322. As can be appreciated, the embodiment of FIGS. 3A and 3B does not rely on compressed gas to fill the airbag, but instead relies on the expansion of the outer walls of the airbag, thus causing a lower pressure in the interior and the drawing in of atmospheric air through the valve 322.

Referring to FIGS. 4A and 4B, another embodiment of an airbag system 400 is illustrated. In FIG. 4A, a collapsed airbag is illustrated. The airbag may be formed from an exterior thin membrane 402 and interior thin membrane 404. There are two closed spaces created from the exterior 402 and interior 404 membranes. There is an interspace created between the interior membrane 404 and the exterior membrane 402, and an interior chamber created from the interior of the membrane 404, such that the interspace is closed from the interior chamber. The airbag may be described as a bag within a bag. The interspace is connected to a pressurized gas cylinder 406, whereas the interior chamber is connected via a one-way valve 408 to the ambient atmosphere.

As illustrated in FIG. 4B, when the pressurized gas cylinder 406 is deployed, the gas enters into the interspace between the interior 404 and exterior 402 membranes, thereby causing the space between membranes 402 and 404 to expand outward. The outward expansion creates a lower pressure in the interior of the membrane 404 as compared to the exterior ambient atmosphere, thereby drawing in air via the one-way valve 408.

Referring to FIG. 5, another embodiment is illustrated wherein the airbag includes a rib structure 504 similar to the rib structure described in connection with FIGS. 1 A and 1B. However, instead of a pressurized gas cylinder, the embodiment of FIG. 5 uses a forced air device such as a fan to inflate the rib structure 504. The rib structure 504 is a closed system and is provided with a separate and distinct gas source as compared to the airbag chamber 506, which is fed via the one-way valve 512.

Some embodiments relate to a method of inflating an airbag. The method includes inflating a collapsed inflatable frame that supports and expands walls of an airbag, creating a lower pressure in the interior of the airbag as compared to the exterior during expansion of the inflatable frame, while allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag.

In some embodiments, the airbag is fluidly connected to a forced air device, such as a battery operated fan.

In some embodiments, the frame comprises inflatable ribs placed along the airbag walls.

In some embodiments, the frame comprises inflatable ribs that are formed by welding an outer membrane with an inner membrane.

In some embodiments, the frame comprises an enclosed pocket surrounding a majority of the airbag wall surface.

Some embodiments further include inflating the inflatable frame to a pressure to make the frame rigid.

In some embodiments, the frame receives gas from a gas storage device, and the airbag receives gas from the atmosphere.

In some embodiments, the gas storage device further includes a Venturi valve to increase the amount of air that is pushed into the airbag.

In some embodiments, the inflatable frame has a capacity that is less than a capacity of the airbag.

In some embodiments, the inflatable frame receives gas from a source that is a different source than the gas used to inflate the airbag.

Some embodiments relate to a method of inflating an airbag. The method includes, with a device, expanding a collapsed or folded frame that supports and expands airbag walls, creating a lower pressure in the interior of the airbag as compared to the exterior, and allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag, wherein the frame comprises rigid interconnecting members.

In some embodiments, the device is a torsion spring.

In some embodiments, the frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.

In some embodiments, the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.

Some embodiments are related to an airbag, which includes a thin membrane formed into a collapsed deflated bag with an inlet in communication to the atmosphere, a collapsed frame that is attached to walls of the bag, and a device connected to the frame, wherein the device is configured to expand the frame.

In some embodiments, the device includes a torsion spring connected to the frame.

In some embodiments, the collapsed frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.

In some embodiments, the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.

Some embodiments are related to an airbag, which includes a first thin interior membrane formed into a collapsed deflated bag with an inlet that allows air to enter from the atmosphere, a second thin exterior membrane juxtaposed on and surrounding the first thin membrane, wherein a first inflatable volume is created between the first and second membranes, and a second inflatable volume is create in the interior of the first membrane, wherein the capacity of the first inflatable volume is less than the second inflatable volume.

In some embodiments, the first inflatable volume is connected to a compressed gas cylinder, and the second inflatable volume is connected to the ambient atmosphere.

In some embodiments, the first inflatable volume is connected to a forced air device.

In some embodiments, the first inflatable volume is connected to the second inflatable volume via a one-way valve.

The features of any one embodiment may be combined with any other embodiment, or certain features may be omitted from any one embodiment, as well.

The principle used in the disclosed embodiments for inflating the airbag is to expand a frame that supports and is connected to an airbag, thereby expanding the walls of the airbag. Upon expansion of airbag walls using a type of expanding frame, the airbag chamber experiences a lower pressure on the inside of the chamber as compared to the ambient exterior atmosphere, thereby causing air to rush into the airbag chamber.

Embodiments of the airbag disclosed herein may be deployed in various ways. For example, the user may use a ripcord to activate the gas canister or release a pin that unlocks a spring device. Alternatively, the gas canister or spring may be triggered automatically, for example, via a pressure switch, an accelerometer, a push button, and the like. Embodiments of the airbags disclosed herein may be used in burial prevention safety devices to avoid burial in avalanches.

While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. 

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. A method of inflating an airbag, comprising: inflating a collapsed inflatable frame that supports and expands walls of an airbag and creating a lower pressure in the interior of the airbag as compared to the exterior during expansion of the inflatable frame, while allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag.
 2. The method of claim 1, wherein the airbag is fluidly connected to a forced air device.
 3. The method of claim 1, wherein the frame comprises inflatable ribs placed along the airbag walls.
 4. The method of claim 1, wherein the frame comprises inflatable ribs that are formed by welding an outer membrane with an inner membrane.
 5. The method of claim 1, wherein the frame comprises an enclosed pocket surrounding a majority of the air bag wall surface.
 6. The method of claim 1, further comprising inflating the inflatable frame to a pressure to make the frame rigid.
 7. The method of claim 1, wherein the frame receives gas from a gas storage device, and the airbag receives gas from the atmosphere.
 8. The method of claim 1, wherein the gas storage device further includes a Venturi valve.
 9. The method of claim 1, wherein the inflatable frame has a capacity that is less than a capacity of the airbag.
 10. The method of claim 1, wherein the inflatable frame receives gas from a source that is a different source than the gas used to inflate the airbag.
 11. A method of inflating an airbag, comprising: with a device, expanding a collapsed or folded frame that supports and expands airbag walls, creating a lower pressure in the interior of the airbag as compared to the exterior, and allowing gas to be drawn into the airbag due to the lower pressure to fill the airbag, wherein the frame comprises rigid interconnecting members.
 12. The method of claim 11, wherein the device is a torsion spring.
 13. The method of claim 11, wherein the frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.
 14. The method of claim 11, wherein the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.
 15. An airbag, comprising: a thin membrane formed into a collapsed deflated bag with an inlet in communication to the atmosphere, a collapsed frame that is attached to walls of the bag, and a device connected to the frame, wherein the device is configured to expand the frame.
 16. The airbag of claim 15, wherein the device includes a torsion spring connected to the frame.
 17. The airbag of claim 15, wherein the collapsed frame comprises a plurality of arc-shaped members, wherein each member comprises two sides, and the members are connected to each other about a pivoting point on the same corresponding side.
 18. The airbag of claim 15, wherein the airbag comprises a first and second rigid plate on opposing sides, and a flexible membrane connects the first plate to the second plate to form the airbag.
 19. An airbag, comprising: a first thin interior membrane formed into a collapsed deflated bag with an inlet that allows air to enter from the atmosphere, a second thin exterior membrane juxtaposed on and surrounding the first thin membrane, wherein a first inflatable volume is created between the first and second membranes, and a second inflatable volume is create in the interior of the first membrane, wherein the capacity of the first inflatable volume is less than the second inflatable volume.
 20. The airbag of claim 19, wherein the first inflatable volume is connected to a compressed gas cylinder, and the second inflatable volume is connected to the ambient atmosphere.
 21. The airbag of claim 19, wherein the first inflatable volume is connected to a forced air device.
 22. The airbag of claim 19, wherein the first inflatable volume is connected to the second inflatable volume via a one-way valve. 